OFFSET
0,3
COMMENTS
((-1)^(n+1))*a(n) = S_{-7}(n), n>=0, defined in A092184.
LINKS
FORMULA
a(n)= 2*(T(n, 9/2)-(-1)^n)/11, with twice Chebyshev's polynomials of the first kind evaluated at x=9/2: 2*T(n, 9/2)=A056918(n)=((9+sqrt(77))^n + (9-sqrt(77))^n)/2^n.
a(n)= 9*a(n-1)-a(n-2)+2*(-1)^(n+1), n>=2, a(0)=0, a(1)=1.
a(n)= 8*a(n-1) + 8*a(n-2) - a(n-3), n>=3, a(0)=0, a(1)=1, a(2)=7.
G.f.: x*(1-x)/((1+x)*(1-9*x+x^2)) = x*(1-x)/(1-8*x-8*x^2+x^3) (from the Stephan link, see A092184).
MATHEMATICA
LinearRecurrence[{8, 8, -1}, {0, 1, 7}, 20] (* Harvey P. Dale, Jan 01 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Oct 18 2004
STATUS
approved